With infrequent exception, internal combustion engines are started by "cranking" the engine using a starter motor which draws electricity from a storage battery. A passenger auto is perhaps the most common example of such an arrangement although it is certainly not the only example.
Another example is an engine-generator set used to provide electrical power when no utility power is available or easily available. Such sets are often used at construction sites and are started by depressing a button or the like. And when a set is used to provide power in the event of a utility power failure, it is often referred to as a "standby" power unit. Hospitals are commonly equipped with such power units. If commercial power fails, the engine starts automatically, using a starter motor and battery as described above.
In the foregoing examples, the electrical "charge" in the battery is maintained by a rotating, dynamo-type generator or alternator and in this specification, the term "alternator" means either generator or alternator. Very typically, the alternator includes a drive pulley engaged by the same fan belt which drives the engine cooling fan, the water pump and perhaps other auxiliary equipment. Commonly, the alternator is mounted by a bolt securing one alternator mounting "ear" to the engine block and a second mounting ear to a slotted arm of some type which protrudes away from the block. U.S. Pat. No. 4,849,665 (Kitamura et al. shows such an arrangement. Other examples of engine-driven alternators are disclosed in U.S. Pat. Nos. 4,288,712 (Hagenlocher et al.); 4,546,280 (Pfluger); 4,604,538 (Merrill et al.); 4,680,495 (Chiampas et al.) and many others.
Mounting an alternator and its voltage regulator in operative relationship to the prime mover engine involves a number of design considerations. Among them are available space, the number of different engine configurations with which the alternator is to be used, alternator component cooling and simply the ease of mounting.
If the engine is in an enclosure, available space may be at a premium--many other components in addition to the alternator must be mounted in close proximity to the engine. And even if no enclosure is used, it is preferred that the alternator be mounted very close to the engine. A known alternator mounting arrangement has the alternator protruding sideways well beyond the engine block. So positioned, it is not surprising that passing equipment may strike and damage the alternator.
If an alternator is to be used with but a single engine, the alternator may be configured for optimal mounting to such engine. But, often, a manufacturer wishes to provide more mounting flexibility by configuring the alternator to mount easily on different engines.
The alternator disclosed in the Hagenlocher et al. patent is an example and includes a shell having an integral attachment projection. One end of the shell is covered by an end shield having an integral positioning arm. The attachment portion and positioning arm receive bolts for alternator mounting. At least that edge of the shell to which the end shield attaches is hex-shaped as is the shield. Therefore, the shield and shell can be mounted in any of six (effectively, five) different mounting positions with respect to one another. But, of course, this can be accomplished in the field only by removing the shield and that involves significant disassembly.
At the least, the matter of alternator component cooling involves properly cooling the voltage regulator. The Pfluger and Chiampas et al. patents noted above and U.S. Pat. No. 4,705,983 (Franz et al.) all show voltage regulators enclosed in some sort of housing. Seemingly, the rate of air flow thereacross will be less than optimal and the temperature in the housing is likely to be higher than outside such housing.
Another known way of mounting a voltage regulator is on a bracket or support separate from the alternator. Wires and a plug connect the alternator and the voltage regulator to one another. While regulator cooling is satisfactory with this arrangement, the installer needs to mount two separate components--and separately replace them when making repairs.
An improved electrical alternator which addresses disadvantages of earlier, known arrangements would be an important advance in the art.